Broadcasters of television programs, transmitted directly or by way of decoder boxes (“Set Top Box”, to use the term well known to the person skilled in the art), sometimes transmit a dual audio content (two different audio programs) associated with a single video channel, so as to provide additional services to their customers (for example, a program associated with an audiodescription of this program for partially-sighted people).
The transmission of multiple audio contents is becoming increasingly common, and their decoding is supported by most television sets and current decoders.
A problem appears when it is desired to listen to the two audio contents at the same time, using the loudspeakers of a television for example.
Indeed, as the right and left loudspeakers generally have wide directivity, it is not possible to deliver the sound of the two audio programs simultaneously (for example, by using the left loudspeaker for a first or the left program and the right loudspeaker for a second or the right program). Indeed, the sound will be mixed acoustically and the people watching the television will hear the two audio programs simultaneously.
This problem also appears with game consoles when two players are playing on the same screen. Indeed, although the two players can share the same atmospheric music, it is not desirable for the sounds generated by that part of the game intended for one player to be able to be heard by the other player.
A conventional solution consists in broadcasting a first audio content on the loudspeakers while a second audio content is broadcast on a headset pick-up.
However, with such a solution, a person wishing to listen to an auxiliary audio program must purchase an additional piece of equipment (for example a headset) so as to be capable of listening to his audio program without bothering the other listener. Moreover, the number of people watching the program is limited by the number of headsets that can be connected to the television.